I have a few limbers, although not as many as there are batteries, in my 15/18mm Napoleonic armies. When I remember, they mark the position of batteries on the move and are replaced by the guns when unlimbered. So they are just markers. It is rare to have more than one or two batteries on the move at any time, so I don’t need very many. I’ve also been known (heresy, heresy) to use limbers from another army (preferably an allied one) if nothing else is readily to hand. I don’t mind doing the occasional limber model; that is infrequent enough to be a change.
For other periods I rarely do limbers or other transport. No real excuse, except the rules I currently use don’t call for them.
Maybe it is a bit of a ‘scale’ thing. I can see the difficulty at 28mm, whereas 6mm units tend towards diorama, lending themselves to limbers with artillery, and other such paraphernalia.